gator: Version 5.18

Signed-off-by: Jon Medhurst <tixy@linaro.org>

1 files changed, 56 insertions, 26 deletions

diff --git a/drivers/gator/gator_cookies.c b/drivers/gator/gator_cookies.c
index 91adfdde9be..5c7d842070e 100644
--- a/drivers/gator/gator_cookies.c
+++ b/drivers/gator/gator_cookies.c
@@ -1,5 +1,5 @@
 /**
- * Copyright (C) ARM Limited 2010-2013. All rights reserved.
+ * Copyright (C) ARM Limited 2010-2014. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -15,17 +15,22 @@
 static uint32_t *gator_crc32_table;
 static unsigned int translate_buffer_mask;
 
+struct cookie_args {
+	struct task_struct *task;
+	const char *text;
+};
+
 static DEFINE_PER_CPU(char *, translate_text);
 static DEFINE_PER_CPU(uint32_t, cookie_next_key);
 static DEFINE_PER_CPU(uint64_t *, cookie_keys);
 static DEFINE_PER_CPU(uint32_t *, cookie_values);
 static DEFINE_PER_CPU(int, translate_buffer_read);
 static DEFINE_PER_CPU(int, translate_buffer_write);
-static DEFINE_PER_CPU(void **, translate_buffer);
+static DEFINE_PER_CPU(struct cookie_args *, translate_buffer);
 
 static uint32_t get_cookie(int cpu, struct task_struct *task, const char *text, bool from_wq);
 static void wq_cookie_handler(struct work_struct *unused);
-DECLARE_WORK(cookie_work, wq_cookie_handler);
+static DECLARE_WORK(cookie_work, wq_cookie_handler);
 static struct timer_list app_process_wake_up_timer;
 static void app_process_wake_up_handler(unsigned long unused_data);
 
@@ -109,36 +114,62 @@ static void cookiemap_add(uint64_t key, uint32_t value)
 }
 
 #ifndef CONFIG_PREEMPT_RT_FULL
-static void translate_buffer_write_ptr(int cpu, void *x)
+static void translate_buffer_write_args(int cpu, struct task_struct *task, const char *text)
 {
-	per_cpu(translate_buffer, cpu)[per_cpu(translate_buffer_write, cpu)++] = x;
-	per_cpu(translate_buffer_write, cpu) &= translate_buffer_mask;
+	unsigned long flags;
+	int write;
+	int next_write;
+	struct cookie_args *args;
+
+	local_irq_save(flags);
+
+	write = per_cpu(translate_buffer_write, cpu);
+	next_write = (write + 1) & translate_buffer_mask;
+
+	// At least one entry must always remain available as when read == write, the queue is empty not full
+	if (next_write != per_cpu(translate_buffer_read, cpu)) {
+		args = &per_cpu(translate_buffer, cpu)[write];
+		args->task = task;
+		args->text = text;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 39)
+		get_task_struct(task);
+#endif
+		per_cpu(translate_buffer_write, cpu) = next_write;
+	}
+
+	local_irq_restore(flags);
 }
 #endif
 
-static void *translate_buffer_read_ptr(int cpu)
+static void translate_buffer_read_args(int cpu, struct cookie_args *args)
 {
-	void *value = per_cpu(translate_buffer, cpu)[per_cpu(translate_buffer_read, cpu)++];
-	per_cpu(translate_buffer_read, cpu) &= translate_buffer_mask;
-	return value;
+	unsigned long flags;
+	int read;
+
+	local_irq_save(flags);
+
+	read = per_cpu(translate_buffer_read, cpu);
+	*args = per_cpu(translate_buffer, cpu)[read];
+	per_cpu(translate_buffer_read, cpu) = (read + 1) & translate_buffer_mask;
+
+	local_irq_restore(flags);
 }
 
 static void wq_cookie_handler(struct work_struct *unused)
 {
-	struct task_struct *task;
-	char *text;
+	struct cookie_args args;
 	int cpu = get_physical_cpu(), cookie;
-	unsigned int commit;
 
 	mutex_lock(&start_mutex);
 
 	if (gator_started != 0) {
-		commit = per_cpu(translate_buffer_write, cpu);
-		while (per_cpu(translate_buffer_read, cpu) != commit) {
-			task = (struct task_struct *)translate_buffer_read_ptr(cpu);
-			text = (char *)translate_buffer_read_ptr(cpu);
-			cookie = get_cookie(cpu, task, text, true);
-			marshal_link(cookie, task->tgid, task->pid);
+		while (per_cpu(translate_buffer_read, cpu) != per_cpu(translate_buffer_write, cpu)) {
+			translate_buffer_read_args(cpu, &args);
+			cookie = get_cookie(cpu, args.task, args.text, true);
+			marshal_link(cookie, args.task->tgid, args.task->pid);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 39)
+			put_task_struct(args.task);
+#endif
 		}
 	}
 
@@ -169,15 +200,14 @@ static int translate_app_process(const char **text, int cpu, struct task_struct
 	//   inconsistent during a context switch between android/linux versions
 	if (!from_wq) {
 		// Check if already in buffer
-		int ptr = per_cpu(translate_buffer_read, cpu);
-		while (ptr != per_cpu(translate_buffer_write, cpu)) {
-			if (per_cpu(translate_buffer, cpu)[ptr] == (void *)task)
+		int pos = per_cpu(translate_buffer_read, cpu);
+		while (pos != per_cpu(translate_buffer_write, cpu)) {
+			if (per_cpu(translate_buffer, cpu)[pos].task == task)
 				goto out;
-			ptr = (ptr + 2) & translate_buffer_mask;
+			pos = (pos + 1) & translate_buffer_mask;
 		}
 
-		translate_buffer_write_ptr(cpu, (void *)task);
-		translate_buffer_write_ptr(cpu, (void *)*text);
+		translate_buffer_write_args(cpu, task, *text);
 
 		// Not safe to call in RT-Preempt full in schedule switch context
 		mod_timer(&app_process_wake_up_timer, jiffies + 1);
@@ -340,7 +370,7 @@ static int cookies_initialize(void)
 		}
 		memset(per_cpu(cookie_values, cpu), 0, size);
 
-		per_cpu(translate_buffer, cpu) = (void **)kmalloc(TRANSLATE_BUFFER_SIZE, GFP_KERNEL);
+		per_cpu(translate_buffer, cpu) = (struct cookie_args *)kmalloc(TRANSLATE_BUFFER_SIZE, GFP_KERNEL);
 		if (!per_cpu(translate_buffer, cpu)) {
 			err = -ENOMEM;
 			goto cookie_setup_error;